A wide variety of intravascular catheters have been developed to diagnose and treat vascular diseases. Some types of catheters include a curved or shaped distal portion. The curved or shaped portion is used in order to facilitate navigation of the catheter through the vasculature. The curved or shaped portion allows the catheter to make sharp bends or follow tortuous passages not easily achieved using other catheters.
Some catheters used for diagnosing and treating vascular diseases are generally comprised of an inner layer, a reinforcing layer, and an outer layer. The outer layer may include a plurality of segments placed along the length of the catheter. The segments may have different mechanical properties and/or materials, thus varying the rigidity, flexibility, and torqueability of the catheter along its shaft. For example, in selecting a useful combination of segments in forming the outer layer, a catheter may be created having a flexible distal region while maintaining a more rigid proximal region with a higher torqueability. The flexible distal tip region will allow the catheter to navigate tortuous regions of the vasculature while the more rigid proximal region will allow the catheter to be longitudinally pushed through the vasculature. It is necessary to bond these segments of varying properties or materials together or to the rest of the catheter shaft in order to create a generally continuous catheter shaft.